Condensed Matter Theory Seminar - Rufus Boyack - Dartmouth College

Anomalous scaling dimensions of monopole operators in Gross-Neveu Yukawa theories

Quantum phase transitions involving the Dirac spin liquid are described by conformal field theories (CFT) in 2 + 1 dimensions with massless Dirac fermions. The transitions to other spin liquids or antiferromagnetic phases are described by three-dimensional quantum electrodynamics (QED3) with a Gross-Neveu interaction. An important order parameter for the antiferromagnetic phases are monopole operators.

I will present calculations of anomalous scaling dimensions in several QED3-GN theories using a large-N expansion to subleading order in 1/N. In addition, I will discuss the large-charge expansion and show that the constant coefficient matches the universal nonperturbative prediction for CFTs with a global U(1) symmetry. I will also discuss the analogous monopole scaling dimensions for GN theories without a gauge field and show that monopole operators can be understood using dualities. The associated large-charge expansions will be shown to not have the universal term due to a Higgs-like mechanism. 

Host: Shankar Ganesh